/*
   Bacula® - The Network Backup Solution

   Copyright (C) 2000-2007 Free Software Foundation Europe e.V.

   The main author of Bacula is Kern Sibbald, with contributions from
   many others, a complete list can be found in the file AUTHORS.
   This program is Free Software; you can redistribute it and/or
   modify it under the terms of version two of the GNU General Public
   License as published by the Free Software Foundation and included
   in the file LICENSE.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

   Bacula® is a registered trademark of John Walker.
   The licensor of Bacula is the Free Software Foundation Europe
   (FSFE), Fiduciary Program, Sumatrastrasse 25, 8006 Zürich,
   Switzerland, email:ftf@fsfeurope.org.
*/
/*
 * Block definitions for Bacula media data format.
 *
 *    Kern Sibbald, MM
 *
 *   Version $Id: block.h 4992 2007-06-07 14:46:43Z kerns $
 *
 */


#ifndef __BLOCK_H
#define __BLOCK_H 1

#define MAX_BLOCK_LENGTH  (1024*1024 + 1) /* this is a sort of sanity check */
#define DEFAULT_BLOCK_SIZE (512 * 126)  /* 64,512 N.B. do not use 65,636 here */

/* Block Header definitions. */
#define BLKHDR1_ID       "BB01"
#define BLKHDR2_ID       "BB02"
#define BLKHDR_ID_LENGTH  4
#define BLKHDR_CS_LENGTH  4             /* checksum length */
#define BLKHDR1_LENGTH   16             /* Total length */
#define BLKHDR2_LENGTH   24             /* Total length */

#define WRITE_BLKHDR_ID     BLKHDR2_ID
#define WRITE_BLKHDR_LENGTH BLKHDR2_LENGTH
#define BLOCK_VER               2

/* Record header definitions */
#define RECHDR1_LENGTH      20
#define RECHDR2_LENGTH      12
#define WRITE_RECHDR_LENGTH RECHDR2_LENGTH

/* Tape label and version definitions */
#define BaculaId    "Bacula 1.0 immortal\n"
#define OldBaculaId "Bacula 0.9 mortal\n"
#define BaculaTapeVersion 11
#define OldCompatibleBaculaTapeVersion1  10
#define OldCompatibleBaculaTapeVersion2   9


/*
 * This is the Media structure for a block header
 *  Note, when written, it is serialized.

   uint32_t CheckSum;
   uint32_t block_len;
   uint32_t BlockNumber;
   char     Id[BLKHDR_ID_LENGTH];

 * for BB02 block, we also have

   uint32_t VolSessionId;
   uint32_t VolSessionTime;
 */

class DEVICE;                         /* for forward reference */

/*
 * DEV_BLOCK for reading and writing blocks.
 * This is the basic unit that is written to the device, and
 * it contains a Block Header followd by Records.  Note,
 * at times (when reading a file), this block may contain
 * multiple blocks.
 *
 *  This is the memory structure for a device block.
 */
struct DEV_BLOCK {
   DEV_BLOCK *next;                   /* pointer to next one */
   DEVICE *dev;                       /* pointer to device */
   /* binbuf is the number of bytes remaining in the buffer.
    *   For writes, it is bytes not yet written.
    *   For reads, it is remaining bytes not yet read.
    */
   uint32_t binbuf;                   /* bytes in buffer */
   uint32_t block_len;                /* length of current block read */
   uint32_t buf_len;                  /* max/default block length */
   uint32_t BlockNumber;              /* sequential Bacula block number */
   uint32_t read_len;                 /* bytes read into buffer, if zero, block empty */
   uint32_t VolSessionId;             /* */
   uint32_t VolSessionTime;           /* */
   uint32_t read_errors;              /* block errors (checksum, header, ...) */
   int      BlockVer;                 /* block version 1 or 2 */
   bool     write_failed;             /* set if write failed */
   bool     block_read;               /* set when block read */
   int32_t  FirstIndex;               /* first index this block */
   int32_t  LastIndex;                /* last index this block */
   char    *bufp;                     /* pointer into buffer */
   POOLMEM *buf;                      /* actual data buffer */
};

#define block_is_empty(block) ((block)->read_len == 0)

#endif